@article{9878,
  abstract     = {{(K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders.}},
  author       = {{Isobe, G. and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}},
  issn         = {{0885-3010}},
  journal      = {{Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on}},
  keywords     = {{Q-factor, ceramics, crystal growth from solution, particle size, piezoelectric materials, potassium compounds, powders, sintering, sodium compounds, ultrasonic effects, (K0.48Na0.52)NbO3, KNbO3 powders, NaNbO3 powders, high-power ultrasonic irradiation, lead-free piezoelectric materials, lead-free piezoelectric powders, particle size reduction, piezoelectric properties, quality factor, sintered (K0.48Na0.52)NbO3 ceramics, sintering, ultrasonic-assisted hydrothermal method, Acoustics, Ceramics, Lead, Piezoelectric materials, Powders, Radiation effects, Transducers}},
  number       = {{2}},
  pages        = {{225--230}},
  title        = {{{Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics}}},
  doi          = {{10.1109/TUFFC.2014.6722608}},
  volume       = {{61}},
  year         = {{2014}},
}

@inproceedings{9785,
  abstract     = {{Hydrothermal method enables to synthesize high quality piezoelectric materials. To shorten the reaction time and to get higher quality materials, we propose an ultrasonic irradiation to the solution during the hydrothermal method. We named it ultrasonic assisted hydrothermal method (UAHTM). We have synthesized lead-free piezoelectric material and PZT thin film and the effect of UAHTM have been confirmed. In this study, we tried to improve UAHTM. First, to generate powerful and stable ultrasonic irradiation at high temperature on UAHTM, we developed a new transducer using LiNbO3 single crystal. Second, to prevent contamination to the materials, A Teflon cover on the tip of transducer was attached.}},
  author       = {{Isobe, Gaku and Ageba, Ryo and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}},
  booktitle    = {{AIP Conference Proceedings}},
  editor       = {{B. J. Linde, Bogumil and Paczkowski, Jacek and Ponikwicki, Nikodem}},
  keywords     = {{contamination, lead compounds, piezoelectric materials, piezoelectric thin films, piezoelectric transducers, ultrasonic effects}},
  number       = {{1}},
  pages        = {{569--572}},
  publisher    = {{AIP}},
  title        = {{{Synthesis of piezoelectric materials by ultrasonic assisted hydrothermal method}}},
  doi          = {{10.1063/1.3703251}},
  volume       = {{1433}},
  year         = {{2012}},
}